The adaptation of mechanical key-operated locks to incorporate electrical switch components typically has involved the use of a considerable number of individual parts stacked up on the rear end of the lock cylinder. Such arrangements increase the cost of production and assembly as well as imposing problems and difficulties in the type of assembly operations that can be performed. In addition, the ability to disembowel the lock to change keys and to change contact carrying elements has either been nonexistent or was present by way of a specialty design that is not easily accomplished.
One more recent approach toward eliminating the stack up arrangements of conventional switch locks in connection with an axial split pin tumbler type of lock is disclosed in Frank J. Scherbing U.S. Pat. No. 4,147,905 issued Apr. 3, 1979 and entitled "Sleeve and Terminal Holder Assembly For An Axial Split Pin Tumbler Type Switch Lock Mechanism". There, the pin tumbler sleeve and electrical contact actuating elements some of which being molded plastic members can be assembled somewhat like a so-called "Chinese puzzle" and then inserted into the lock cylinder as a unit. While that arrangement does provide elimination of many parts of a typical stacked up switch lock construction and the realization of cost savings in manufacture, it is essentially a single, specialty design of an axial pin tumbler lock and there is no real versatility of optional features that can be included with the same switch actuating components. Thus, a lock manufacturer with various types of locks and optional features available to be included with such locks would still not be able to offer the same set of elements for electrical switching to be applied with any of a number of such locks in the line. Also, the arrangement of the aforementioned patent as well as prior conventionally utilized forms of switch locks did not contemplate any provision for easy disembowelment to change keys and other elements of the lock after it was fixedly assembled.
Accordingly, it is the primary object of the invention to provide an improved switch actuating subassembly for a mechanical key-actuated lock which includes a relatively small number of easy to produce parts, affects cost savings in production and assembly, and which can be utilized in conjunction with a variety of forms of locks including various optional features readily available with such locks. It is a related object to provide an improved switch actuating subassembly that can be easily incorporated in the most commonly utilized size of axial pin tumbler lock casing with only a slight amount of modification being necessary to accommodate the switch mechanism.
Another object is to provide such an improved switch lock arrangement which permits the various components of the lock to be easily disassembled for re-keying and changing of the contact elements.